Keiko Furukura has an uncannily intense relationship with the Hiiromachi Station Smile Mart, where she’s worked for 18 years. She describes it as one might a lover: the sound “ceaselessly caresses my eardrums”; when absent, “I picture the brightly lit and bustling store, and I silently stroke my right hand, its nails neatly trimmed in order to better work the buttons on the cash register.”

Keiko has always struggled to behave appropriately. She recalls being at nursery school, seeing a dead bird and exclaiming: “Let’s grill it and have it for dinner!” As an adult, she watches her sister soothe her crying baby: “I looked at the small knife we’d used to cut the cake still lying there on the table: if it was just a matter of making him quiet, it would be easy enough.” When working in the convenience store, however, Keiko knows exactly what to do. There is a training manual to follow, she can mimic her co-workers’ intonation, and understands exactly how to meet sales targets and please customers; she feels “reborn” as a “normal cog in society”, “a being with meaning”. Unfortunately, society can’t accept that a 36-year-old woman is content in this dead-end job, with no husband or child.

Murata uses Keiko’s existence outside society’s expectations to highlight just how arbitrary and peculiar convention can be. So her sister is relieved when Keiko starts living with a man, even though she thinks he is lazy and unfaithful. “She’s far happier thinking her sister is normal, even if she has a lot of problems, than she is having an abnormal sister for whom everything is fine.”

The novel is steeped in Japanese anxiety about rising celibacy, declining birth rate and hikikomori(a form of acute social withdrawal that affects over half a million Japanese people, who remain in their apartments sometimes for years at a time). Murata shines an unflinching light on her native country, and her book has struck a chord there, selling more than 650,000 copies and winning the prestigious Akutagawa prize. For readers who are less familiar with Japan, Murata conjures it in all its fascinating otherness, while giving us a protagonist whose tussle with accepting who she is while trying to fit in is universally familiar.

• Convenience Store Woman is written by Sayaka Murata, translated by Ginny Tapley Takemori and published by Granta. To order a copy for £11.04 (RRP £12.99) go to guardianbookshop.com or call 0330 333 6846. Free UK p&p over £10, online orders only. Phone orders min p&p of £1.99.